Power Supply Failure?

I've replaced two power supplies on a intel Mb and Cpu and get absolutely no power to the fans. One power supply does turn the Mb light on but no fans. Shouldn't I have some DC voltage to the connectors, I have none with either PS and I thought they were good? I've had them for several years.any ideas?thanks

The power supply is a Antec 350 smart power and it does light the green light next to the 24 pin connector. The motherboard is a intel D915PBL. I built this for my grandson a few years back (7-8?)and can't remember the processor size. It has a Nvidia GF6600QT 128mb ddr3(P216)nvidia video card, IDE dvd drive and 2 sata hard drives with all 4 memory slots filled-that's it.

I forgot to add that I get no beeps no nothing, no fans nada and thats with everything hooked up and ALSO with only video card and ram installed everything else unhooked. The only thing on is the green light next to the 24 pin connector.

Yeah, I'd question if these are truly good PSUs or if, as often happens, you're actually troubleshooting with leftover parts form abandoned or dead systems. If you don't have access to a power supply tester (randomly selected from a quick Amazon search) that can check voltages, or a multimeter, you need to use a PSU pulled from a known working system and see if that powers yours up.

Only 2 PS-I checked both power supplies with a DC meter at the 4 pin connectors to the dvd and also to the fans on both units as they were the easiest. Checked Black to red and black to yellow nothing. I don't know how to check the sata connectors.

I can't remember if the seperate PS was good or not. I do have a seperate complete MB without a case that is good. How do you test a PS or MB outside the Case?

If the systems were powered on, you should be seeing +5v on red and +12v on yellow.

If the motherboard is bad then obviously it won't get the power supplies to power on. You can short PS_ON to ground, although the voltage readings you get won't be very accurate without any load on the PSU...

If your PSU has a physical switch on the back by the AC plug, then it's a hard switch and that switch would need to be set to ON for anything to work.

If shorting PS_ON does get the PSU to turn on, then something's probably not kosher with the motherboard. (very very very rarely, the switch on your case could be bad, you can these this by disconnecting it from the MB and just momentarily shorting the PWR BUTTON jumper to see-- however the case switch going bad is extremely rare)

It needn't be in a case to be tested. I think by PS_ON, he meant the pin on the PSU's connector. You short that to ground to power up the PSU itself. Here's a site with the pinout. The ones labelled COM are your ground so if you short from one of those to the PS_ON one (green wire, typically but I've seen exceptions), the PSU will fire up and then you can measure voltages.

As was stated earlier, testing without a load (as in without the motherboard on it) is not a great test but, at least, you can tell if it fires up. If it doesn't then ... it's dead.

Got the PS a Corsair Cx430 in and nothing turns on only the green light next to the 24 pin connector. The PS does turn on when jumped so it is good as the others PS did not.

Right now I have hard drives and DVD disconnected still nothing nor did anything turn on when all connected. The Mb does not have on board video, if the video card was bad shouldn't something start up or at least beep?

I have another MB & processor can they be tested outside the case? if so how?

I have another MB & processor can they be tested outside the case? if so how?

Just set them atop a static-safe worksurface and plug 'em in. You will need memory as well if memory serves. You can short the PWR BTN pins on the motherboard together momentarily (the tip of a ballpoint pen is perfect for this) to get it to turn on without a physical power button.